Jan. 10: Sahotra Sarkar has helped protect rainforests in Indonesia, primates and birds in Equatorial Guinea, and salamanders in Texas over a 28-year career straddling biology and philosophy. Now, he appears willing to support an idea to wipe out a couple of species.

Sarkar, professor of philosophy at the University of Texas, Austin, says India needs to debate whether it wants to cautiously adopt a radical new gene-editing technology that he says could be used to selectively eliminate the species of mosquitoes that spread dengue or malaria.

The technology, called CRISPR/Cas9, allows unprecedented precision-editing of genomes and could be used - in a drive against mosquitoes - to introduce a gene that makes all mosquitoes male, thus preventing reproduction and triggering an extinction of their populations.

"It is possible, in principle, to use CRISPR/Cas9 to wipe out mosquitoes. Imagine eliminating dengue-spreading mosquitoes from Calcutta," said Sarkar, who delivered a talk today at Presidency University's bicentennial celebrations. "A rough calculation suggests that you would need to release about 10,000 such gene-edited mosquitoes at about six locations across the city and, over a period of two or three years, we could expect them to be eliminated," he said.

But he warned that the technology has controversial applications and needs to be regulated. "This technology has a good side and it has a troubling side," he told Metro on the sidelines of the conference. "We need wide-ranging public discussions on this."

Sarkar, who completed school in Darjeeling before moving to the US for university studies, has over the years worked with landowners and state officials in Texas to protect salamanders, proposed strategies to protect plants, primates and birds in abandoned cocoa plantations in Equatorial Guinea, and designed plans to protect patches of rainforests in Indonesia.

Sarkar doesn't see any paradox between his conservation efforts and his cautious enthusiasm to discuss the elimination of disease-carrying mosquitoes. His call for a discussion on the merits and risks of CRISPR/Cas9 in India comes against the backdrop of a similar discourse among scientific academies in the US, UK and China, advocating a go-slow strategy that permits regulated research but no field applications yet.

Sarkar said Indian science and policy-making circles would soon need to launch a similar discourse, pointing out that India's Tata Trusts had given the University of San Diego $70 million to use genetic technology to target malaria-causing mosquito populations, among other goals.

India already has scientists and medical experts discussing the implications of CRISPR/Cas9 technology, said Dorairajan Balasubramanian, a senior biologist and former director of the Centre for Cellular and Molecular Biology, Hyderabad, who was among Sarkar's audience at the Presidency lecture.